Two nephews of jailed polygamist leader Warren Jeffs say he uses God's name to brainwash others and is still calling the shots from prison.

Matt Jeffs, 20, and Zack Jeffs, 18, are brothers who broke free of the Fundamentalist Church of Jesus Christ of Latter Day Saints, or FLDS. The group is led by self-described prophet Warren Jeffs, who married more than 80 women, and is serving a life sentence in prison after being convicted of two counts of sexual assault against two underage girls.

ABC News accompanied Matt and Zack as they returned to the notorious community in Hildale, Utah, for the first time since fleeing. Despite standing on a public road outside the FLDS, the message is clear – no outsiders are welcomed. A "God Squad" truck, Jeffs' private security force, roams nearby to make sure no unwanted visitors make it inside the highly guarded community.

To live there is to turn back the clock a hundred years. No Internet, no television, no contact with the outside world. Matt and Zack say every aspect of life -- what people wear, what they eat, even whom they marry -- is still controlled by Jeffs, a man people within the community call their prophet.

A raid in 2008 on the group's Yearning For Zion compound in Eldorado, Texas, brought the FLDS community into the national spotlight. Authorities found a polygamous community and pregnant child brides. In 2011, Jeffs was convicted by a Texas jury of having sex with two girls who were 15 and 12 years old. DNA evidence at the trial proved Jeffs had fathered a child with the 15-year-old girl.

"He's using God's name to brainwash them," Matt said. "I was brainwashed where I was terrified of leaving the community."

In the FLDS community it is believed a man with more wives is more likely to go to heaven.

"My dad has nine wives and around 62 kids," Zack said, as Matt rattled off a list of the mothers' names.

The brothers are featured on TLC's "Breaking the Faith" – a show that follows a group of young people after leaving the FLDS. Matt and Zack are part of a group of former FLDS members on a mission to help others who may want to leave the community. The brothers' father is Lyle Jeffs, a bishop in the FLDS, according to the show's website.

"The family will just look at us like we're the most wicked people on earth," Matt said.

Ben, 20, another former church member featured on the show, says young women don't have the ability to pick up and leave the FLDS as easily as it may sound.

"The only thing they know is their bedroom, the laundry room and the kitchen. And that's it. That's all they know," Ben told ABC News.

The church disputes many of the allegations made against them and their practices seen on the show. According to TLC, the show is based on actual events and situations, but some "incidents and timelines" have been altered to protect former and current church members.

Matt and Zack said that from behind prison walls, Jeffs continues to issue edicts.

"There have been no marriages because he's the only one who can do the marriages," Matt said.

"They can't have kids right now either," Zack added, who says as far as he knows, no woman has had a child since Jeffs was jailed.

When asked if Jeffs is a prophet, Ben bluntly states, "No. He's a psychopath that's in prison for life."

While the brothers are discussing details about the FLDS, a "God Squad" car interrupts the interview.